Heat pumps are now the UK government's preferred replacement for gas boilers, backed by a £7,500 grant and an obligation on boiler manufacturers to sell a rising proportion of heat pumps each year. But the technology only delivers on its promise — low running costs and high efficiency — when the building is properly prepared and the system is correctly designed. This guide covers what heat pumps cost in 2026, what grants are available, how to assess your home's suitability, and the planning rules you need to know.
Types of Heat Pump and Installed Costs
| Type | How It Works | Typical Installed Cost |
|---|---|---|
| Air Source (ASHP) | Extracts heat from outside air; works to −15°C | £7,000–£15,000 |
| Ground Source (GSHP) | Extracts heat via buried ground loops or boreholes | £15,000–£35,000 |
| Water Source (WSHP) | Uses river, lake, or borehole water as heat source | £20,000–£50,000+ (rare; mostly commercial) |
Air source heat pumps (ASHPs) are by far the most common domestic installation. The installed cost includes the external unit, internal buffer vessel or cylinder, pipework, commissioning, and MCS certification documentation. It does not include radiator upgrades or underfloor heating installation, which are additional.
Ground source heat pumps (GSHPs) deliver higher efficiency (COP 3.5–4.5 vs ASHP 2.5–3.5) but require significant land — either 400–600m of horizontal ground loops (requires approximately 600–1,000 m² of accessible garden) or vertical boreholes at around £8,000–£12,000 per 100m depth.
The Boiler Upgrade Scheme (BUS): £7,500 Off
The Boiler Upgrade Scheme, administered by Ofgem and funded by the Department for Energy Security and Net Zero, provides:
- £7,500 grant for air source heat pump installation
- £7,500 grant for ground source heat pump installation
- £5,000 grant for biomass boiler (rural, off-gas-grid properties only)
To access the grant:
- The installer must be MCS-certified (Microgeneration Certification Scheme) — check the register at mcscertified.com
- The property must be in England, Scotland, or Wales (Northern Ireland has a separate scheme)
- The property must not have received a previous BUS grant for the same measure
- There must be no outstanding loft or cavity wall insulation recommendations on the property's EPC (as of the 2023 BUS update — the installer checks this)
- The property must have a valid EPC lodged within the last 10 years
The grant is claimed by the installer directly from Ofgem and passed on to you as a reduction in the installation price — you do not need to apply yourself. However, you should confirm the installer has BUS accreditation before signing a contract, and get written confirmation the grant will be applied.
Is a Heat Pump Right for Your Home?
The most common reason heat pumps underperform in UK homes is that they are installed in buildings not ready to receive them. Your home's EPC rating is the starting point — heat pumps perform best in well-insulated homes rated C or above. Use this checklist:
| Factor | Ideal / Acceptable | Caution |
|---|---|---|
| EPC rating | C or above | D or below — insulate first |
| Loft insulation | 270mm mineral wool | Less than 100mm — upgrade first |
| Cavity wall insulation | Filled | Unfilled cavities — fill first |
| Solid walls | Well-insulated (IWI or EWI) | Uninsulated solid walls significantly reduce viability |
| Radiators | Oversized or UFH | Standard-sized rads — likely need upsizing |
| Hot water cylinder | Yes | Combi-only system — cylinder required |
| Property type | Detached or semi | High-rise flat — ASHP impractical |
If your property has solid walls, read our solid wall insulation guide before committing to a heat pump — fabric-first improvements almost always deliver better payback than mechanical upgrades on an uninsulated building.
The key technical issue is flow temperature. Gas boilers typically circulate water at 70–75°C. Heat pumps operate most efficiently at 45–50°C flow temperature. This lower temperature means existing radiators — sized for 70°C — are undersized for a heat pump. An MCS-approved heat pump installer must conduct a full heat loss calculation (to BS EN 12831) for every room and specify radiator sizes accordingly. This is a regulatory requirement under MCS, not an optional extra.
Underfloor heating (UFH) is ideal for heat pumps because it operates at 35–45°C, well within the heat pump's optimal range.
Running Cost Comparison: Heat Pump vs Gas Boiler
The economics depend on the ratio between electricity and gas unit prices. In mid-2026:
- Average electricity unit price: approximately 24–28p/kWh
- Average gas unit price: approximately 6–8p/kWh
- Ratio: approximately 3:1–4:1
A heat pump with a COP (Coefficient of Performance) of 3.0 produces 3 units of heat per unit of electricity. At a 3:1 electricity/gas price ratio, the running costs are broadly comparable. At COP 3.5+, the heat pump becomes cheaper to run.
An older, poorly-maintained gas boiler running at 80% efficiency in a draughty house will cost more per unit of useful heat than its nominal efficiency suggests. A heat pump in a well-insulated home achieves seasonal performance above COP 3.0 reliably. For a full guide to home energy efficiency improvements that make heat pumps more viable, see our home energy efficiency upgrades guide.
Indicative annual heating cost comparison (3-bed semi, average UK insulation):
| System | Annual Fuel Cost (estimate) |
|---|---|
| Gas combi boiler (85% efficiency) | £900–£1,200 |
| ASHP (COP 2.8, current tariffs) | £950–£1,350 |
| ASHP (COP 3.2, Octopus Cosy/heat pump tariff) | £700–£1,050 |
Specialist heat pump electricity tariffs from providers such as Octopus Energy (Cosy Octopus) and E.ON offer reduced off-peak rates for heat pump users, improving economics by 15–25%.
MCS Certification: Why It Matters
MCS (Microgeneration Certification Scheme) certification is mandatory for:
- Access to the Boiler Upgrade Scheme grant
- Compliance with Building Regulations (heat pump installations are notifiable under Part J/L)
- SEG (Smart Export Guarantee) if you are also adding solar PV
An MCS installation requires:
- A certified installer (check mcscertified.com)
- A heat loss calculation per room
- A correctly sized system with documented design rationale
- Commissioning records and an MCS certificate issued on completion
Do not use an uncertified installer even if the quoted price is lower. You will be ineligible for the £7,500 BUS grant and may face Building Regulations compliance issues.
Planning Permission: Class Q Permitted Development
ASHP installations are Permitted Development under Class Q of the GPDO 2015 in England, subject to conditions:
- The unit must be at least 1 metre from the property boundary
- It must not be installed on a wall or roof facing a highway
- The unit volume must not exceed 0.6 m³ (most domestic units comply)
- Only one unit is permitted per property under PD
- The property must not be in a conservation area, AONB, or World Heritage Site — these require a Householder planning application
Scotland, Wales, and Northern Ireland have their own PD regimes; check with your local planning authority if uncertain.
Typical Payback Periods
| Scenario | Estimated Payback |
|---|---|
| No BUS grant, current energy prices | 10–18 years |
| With £7,500 BUS grant, current energy prices | 6–12 years |
| With BUS grant + heat pump tariff | 5–9 years |
| Well-insulated property, high COP, heat pump tariff | 4–7 years |
Payback improves as gas prices rise relative to electricity — a trend the government's own projections support through 2030 as gas grid costs are rebalanced.
Next Steps with Renovate Me
A heat pump project usually requires fabric improvements first — loft insulation, cavity fill, potentially radiator upgrades. Getting the sequencing right saves money and maximises your grant eligibility. Renovate Me builds you a personalised renovation roadmap that covers fabric-first improvements, heat pump readiness, MCS installer connections, and the correct order of works for your property. Start your free plan today.
Further Reading
- EPC Rating UK: How to Improve Your Score — improving your EPC rating before installing a heat pump maximises performance and may be required for BUS grant eligibility
- Solid Wall Insulation Costs UK — if your home has uninsulated solid walls, this is the single most impactful improvement before a heat pump
- Home Energy Efficiency Upgrades UK — the full spectrum of fabric-first improvements that make heat pumps viable
- Home Extension Costs UK 2025 — if you're extending, factor in heat pump sizing for the new floor area from the outset
- Planning a Bathroom Renovation UK — if you're adding underfloor heating as part of a bathroom renovation, heat pump compatibility is worth planning ahead